Improvement of dehydrogenation performance by adding CeO2 to α-AlH3

The alpha-AlH3 + nCeO(2) (n = 0.5, 1 and 2, mol%) composite materials were prepared by ball milling, and the phase composition and dehydrogenation performance of the composites were investigated. The results revealed that alpha-AlH3 doped with CeO2 could effectively decrease the dehydrogenation temperature. The dehydrogenation onset temperature of alpha-AlH3 + 2 mol% CeO2 dropped to 106 degrees C, which was significantly reduced by 24.3% compared with pure alpha-AlH3. At 100 degrees C, the alpha-AlH3 + 2 mol% CeO2 composite released 3.8 wt% hydrogen within 100 min, while the pure alpha-AlH3 released only 0.12 wt% hydrogen in the same duration. Kissinger analysis indicated that apparent activation energy for hydrogen desorption of alpha-AlH3 was significantly decreased with CeO2 doping. The improvement of dehydrogenation performance was due to the finely dispersed CeH2+x, which was formed by the reaction between CeO2 and alpha-AlH3. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.